TW202340279A - Vinyl alcohol copolymer, resin composition containing same, and resin molded body - Google Patents

Abstract

A vinyl alcohol copolymer according to the present invention includes a vinyl alcohol constituent unit and a C3-C30 olefin constituent unit vinyl alcohol. This copolymer satisfies at least one among the conditions in which: the difference between the melting point and the lowest heat-sealing temperature is 45 DEG C or more; and the lowest heat-sealing temperature is 80 DEG C or less. The copolymer satisfies a predetermined relational expression on the basis of the strength obtained from the ultraviolet absorption detector and the refractive index detector, and the number-average molecular weight, in gel permeation chromatography measurements of said copolymer.

Description

Vinyl alcohol copolymer, resin composition containing the same, and resin molded article

The present invention relates to a vinyl alcohol copolymer, a resin composition containing the same, and a resin molded article.

Vinyl alcohol polymers (hereinafter sometimes abbreviated as "PVA") are one of the few crystalline hydrophilic polymers. Utilizing its excellent water solubility and film properties (strength, oil resistance, film-forming properties, oxygen barrier properties, etc.), PVA series is widely used in emulsifiers, suspending agents, surfactants, fiber processing agents, various adhesives, paper Processing agents, adhesives, films, etc.

PVA lacks formability due to its high crystallinity. It is known that PVA-based PVA that reduces crystallinity improves its molding processability. For example, PVA that reduces crystallinity by reducing the degree of saponification has been manufactured and sold. However, PVA that lowers its saponification degree is criticized for lowering its original strengths of oxygen barrier properties, mechanical properties, and thermal stability. For the reasons mentioned above, it is difficult to achieve both formability and performance.

For example, Patent Document 1 describes PVA containing 2 to 19 mol% of ethylene, and describes that this PVA is excellent in thermal stability, water resistance, gas barrier properties, water vapor barrier properties, and low-temperature storage stability of aqueous solutions.

Patent Document 2 describes PVA containing an olefin having 3 or 4 carbon atoms. Patent Document 3 describes PVA containing an olefin having 4 carbon atoms or less. It is described that these PVA can be melt-formed.

However, it is known that the PVA system described in Patent Document 1 has low secondary processability. Furthermore, the PVA described in Patent Documents 2 and 3 also has insufficient secondary processability, and the correlation between the secondary processability and the manufacturing method is not disclosed at all. Specifically, even if such PVA is made into a thin film by melt molding, secondary processability, such as heat sealability, is insufficient, making it difficult to actually utilize it. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 4772175 [Patent document 2] Japanese Patent Publication No. 49-032657 [Patent Document 3] International Publication No. 2006/011490

[Problem to be solved by the invention]

The present invention aims to solve the above-mentioned problems, and aims to provide a vinyl alcohol copolymer having excellent secondary processability while maintaining the mechanical properties of PVA, a resin composition containing the same, and a resin molded article. [Means used to solve problems]

The present invention includes the following inventions.

[1] A copolymer containing vinyl alcohol structural units and olefin structural units having 3 to 30 carbon atoms, which satisfies the requirement that the difference between the melting point and the minimum heat sealing temperature is 45°C or more, and the minimum heat sealing temperature is satisfied It is at least one below 80℃, and satisfies the following formula, {U1/R1}/{U2/R2}≦0.990 or 1.010≦{U1/R1}/{U2/R2} Here, U1 is made of In the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer, Mn was calculated from the chromatogram obtained by the refractive index detector, and the molecular weight MU1 specified by the following formula was obtained from the ultraviolet absorption detector. The value of the peak intensity of the chromatogram, Log ₁₀ MU1 = Log ₁₀ (Mn) + 0.5 R1, is detected from the refractive index in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer. Calculate Mn from the chromatogram obtained by the refractive index detector using the molecular weight MR1 specified by the following formula: Log ₁₀ MR1 = Log ₁₀ (Mn) + 0.5 U2 system Mn was calculated from the chromatogram obtained by the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer, and the molecular weight MU2 specified by the following formula was calculated from the The value of the peak intensity of the chromatogram obtained by the ultraviolet absorption detector, Log ₁₀ MU2=Log ₁₀ (Mn)-0.5 R2, is measured by the gel permeation chromatography of the copolymer obtained by acetylation of the vinyl alcohol copolymer. Mn is calculated from the chromatogram obtained by the refractive index detector, and the value of the peak intensity of the chromatogram obtained from the refractive index detector is calculated using the molecular weight MR2 specified by the following formula, Log ₁₀ MR2=Log ₁₀ ( Mn)-0.5 and Mn is the number average molecular weight of the copolymer obtained by acetylation of the vinyl alcohol copolymer calculated from the chromatogram obtained by the refractive index detector. [2] The vinyl alcohol copolymer according to [1], wherein the number of carbon atoms contained in the olefin structural unit is 3 to 9. [3] The vinyl alcohol copolymer according to [2], wherein the olefin structural unit is selected from the group consisting of propylene unit, 1-butene unit, cis-2-butene unit, trans-2-butene unit, 2- Methpropylene unit, 1-pentene unit, cis-2-pentene unit, trans-2-pentene unit, 2-methyl-1-butene unit, 2-methyl-2-butene unit, 3 -Methyl-1-butene unit, 1-hexene unit, 1-heptene unit, 1-octene unit, 1-nonene unit, 2-methyl-1-octene unit, and 7-methyl -At least one structural unit from the group of 1-octene units. [4] The vinyl alcohol copolymer according to [3], wherein the olefin structural unit is selected from the group consisting of a propylene unit, a 1-butene unit, a cis-2-butene unit, a trans-2-butene unit, and a 2-butene unit. - at least one structural unit from the group of methacrylic units. [5] The vinyl alcohol copolymer according to [4], wherein the olefin structural unit is a propylene unit. [6] The vinyl alcohol copolymer according to [4], wherein the olefin structural unit is a 2-methacrylene unit. [7] The vinyl alcohol copolymer according to any one of [1] to [6], wherein the content of the olefin structural unit is 0.1 to 60 mol%. [8] The vinyl alcohol copolymer according to any one of [1] to [7], wherein the number average molecular weight (Mn) of the copolymer obtained by acetylating the vinyl alcohol copolymer is 400 to 200,000. [9] The vinyl alcohol copolymer according to any one of [1] to [8], having a degree of saponification of 50 to 100 mol%. [10] The vinyl alcohol copolymer according to any one of [1] to [9], wherein the vinyl alcohol structural unit content is 75 to 99 mol%. [11] The vinyl alcohol copolymer according to any one of [1] to [10], which further contains a hydroxyl-containing structural unit other than the vinyl alcohol structural unit. [12] The vinyl alcohol copolymer according to any one of [1] to [11], which further contains an ethylene structural unit. [13] A resin composition containing the vinyl alcohol copolymer according to any one of [1] to [12]. [14] The resin composition according to [13], which further contains polyvinyl alcohol with a saponification degree of 40 to 100%, modified polyvinyl alcohol with a saponification degree of 40 to 100%, polyvinyl alcohol with a saponification degree of 40 to 100%, At least one polymer from the group consisting of ethylene-vinyl alcohol copolymer with a saponification degree of 100%, polyvinyl butyral with a saponification degree of 40 to 100%, starch, starch derivatives, cellulose and cellulose derivatives. . [15] A resin molded article containing the resin composition according to [13] or [14]. [16] The resin molded article according to [15], which is a film. [17] The resin molded article according to [15], which is fiber. [18] The resin molded article according to [15], which is a gas barrier material. [19] The resin molded article according to [15], which is a polarizing film. [20] The resin molded article according to [15], which is a water-soluble base material. [21] A manufacturing method of a vinyl alcohol copolymer containing vinyl alcohol structural units and olefin structural units having 3 to 30 carbon atoms, and satisfying the requirement that the difference between the melting point and the minimum heat sealing temperature is 45 °C or above, and the minimum heat sealing temperature is at least one of 80 °C or below; the manufacturing method includes: polymerizing an olefin and vinyl acetate under conditions in which the pressure of the olefin fluctuates to obtain a crude copolymer; Saponification step of crude copolymer. [22] The method for producing a vinyl alcohol copolymer according to [21], wherein the average change rate of the pressure of the olefin is 1.0×10 ^-5 Pa/minute or more. [Effects of the invention]

According to the present invention, a resin molded article having both good mechanical properties and excellent secondary processability can be obtained. Due to these characteristics, the resin molded article of the present invention can be used in various applications such as films, fibers, and water-soluble substrates.

[Form used to implement the invention]

(vinyl alcohol copolymer) The vinyl alcohol copolymer of the present invention contains vinyl alcohol structural units and olefin structural units.

(vinyl alcohol structural unit) The vinyl alcohol structural unit is a type of repeating unit and can be obtained, for example, by polymerizing vinyl ester and saponifying it. The vinyl ester is not particularly limited, and examples thereof include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl stearate, vinyl benzoate, and vinyl trifluoroacetate. Vinyl formate, vinyl isobutyrate, vinyl isovalerate, trimethylvinyl acetate, vinyl caproate, vinyl enanthate, vinyl octanoate, vinyl nonanoate, vinyl caprate, vinyl lactate , vinyl belladonna alkyd, vinyl cyclohexanoate, vinyl benzoate, vinyl salicylate, vinyl anisate, vinyl vanillate, vinyl gallate, and vinyl visadedic acid (vinyl versatate), and combinations thereof. Vinyl acetate is preferred because it is versatile and easy to obtain.

The content of the vinyl alcohol structural units in the vinyl alcohol copolymer of the present invention is preferably 40 mol% to 99.9 mol%, more preferably 75 mol% to 99 mol%, and further preferably 80 mol%. %~95 mol%. If the content rate of vinyl alcohol structural units is less than 40 mol%, the strength may be reduced. If the content rate of vinyl alcohol structural units exceeds 99.9 mol%, secondary processability such as heat sealability may be reduced. .

(Olefin structural unit) The olefin structural unit is a unit that can be formed by the polymerization of any olefin such as α-olefin and β-olefin, and is composed of 3 to 30 carbon atoms, more preferably 3 to 9 carbon atoms, and even more preferably 3 to 5 carbon atoms.

The olefin structural unit that may be contained in the vinyl alcohol copolymer of the present invention is preferably a structural unit derived from an ethylenically unsaturated monomer. Examples of olefin structural units derived from ethylenically unsaturated monomers include propylene, 1-butene, cis-2-butene, trans-2-butene, 2-methylpropene (2 -methylpropylene, 2-methylpropene), 1-pentene, cis-2-pentene, trans-2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, and 3- Structural units of methyl-1-butene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, etc., and their combination. In particular, because of good separability from other monomers after copolymerization, the olefin structural units are preferably derived from propylene, 1-butene, cis-2-butene, trans-2-butene, and The structural unit of 2-methacrylene and the combination thereof are further preferably structural units derived from propylene from the viewpoint of easy purification and isolation after the polymerization reaction. On the other hand, from the viewpoint that the obtained vinyl alcohol copolymer is excellent in secondary processability such as heat sealability, 2-methacrylene is preferred.

The content of the above-mentioned olefin structural units in the vinyl alcohol copolymer of the present invention is preferably 0.1 mol% to 60 mol%, more preferably 1 mol% to 30 mol%, and further preferably 3 mol%. ~20 mol%, optimally 5 mol% ~ 15 mol%. If the content of the olefin structural unit is less than 0.1 mol%, secondary processability such as heat sealability may be reduced. If the content of the olefin structural unit exceeds 60 mol%, the molecular weight may decrease and the strength may decrease.

(Structural units containing hydroxyl groups other than vinyl alcohol structural units) The vinyl alcohol copolymer of the present invention may contain hydroxyl-containing structural units other than the above-mentioned vinyl alcohol structural units copolymerizable with the above-mentioned vinyl alcohol structural units and olefin structural units, as long as the effects of the present invention are not inhibited. The hydroxyl-containing structural units other than vinyl alcohol structural units contain hydroxyl groups, or contain functional groups that can be derived into hydroxyl groups. The functional group that can be derived into a hydroxyl group is not particularly limited, and examples thereof include an ester group, a amide group, an ether group, an acetal group, and the like. From the viewpoint of facilitating the production of the vinyl alcohol copolymer itself, the functional group is preferably Ester group. Examples of hydroxyl-containing structural units other than vinyl alcohol structural units include: 1,3-diethyloxy-2-methylenepropane (DAMP), 1,3-dipropyloxy -2-methylenepropane, 1,3-dibutyloxy-2-methylenepropane, 1,3-dihydroxy-2-methylenepropane, allyl alcohol, 3-acetyloxy- 1-Propylene, 3,4-dihydroxy-1-butene, 3,4-diethyloxy-1-butene, 4-hydroxy-2-methyl-1-butene, 4-acetyloxy Structural units such as 2-methyl-1-butene, methallyl alcohol, methylallyl acetate, and combinations thereof. Since polymerization using this structural unit becomes easier, a structural unit derived from DAMP is preferred.

The content rate of hydroxyl-containing structural units other than the vinyl alcohol structural units in the vinyl alcohol copolymer of the present invention is preferably 0.1 mol% to 40 mol%, more preferably 1 mol% to 20 mol%, and further more Preferably, it is 5 mol% to 15 mol%. If the content rate of hydroxyl-containing structural units other than vinyl alcohol structural units is less than 0.1 mol %, the water solubility of the obtained vinyl alcohol copolymer may decrease. If the content rate of the hydroxyl-containing structural unit is higher than 40 mol%, the molecular weight of the resulting vinyl alcohol copolymer may decrease and the strength may decrease.

(Ethylene structural unit) Furthermore, the vinyl alcohol copolymer of the present invention may contain an ethylene structural unit copolymerizable with the above-mentioned vinyl alcohol structural unit and olefin structural unit within a range that does not inhibit the effects of the present invention. The content rate of the above-mentioned ethylene structural unit in the vinyl alcohol copolymer of the present invention is preferably 0.1 mol% to 60 mol%, more preferably 1 mol% to 50 mol%, and further preferably 5 mol% to 5 mol%. 40 mol%, optimally 7 to 20 mol%. If the content rate of the ethylene structural unit is less than 0.1 mol%, the viscosity stability of the aqueous solution may decrease. If the content of the ethylene structural unit is higher than 60 mol%, the strength of the obtained vinyl alcohol copolymer may decrease.

(Other structural units) The vinyl alcohol copolymer of the present invention may contain structural units other than the above within a range that does not inhibit the effects of the present invention. Other structural units are not particularly limited, and examples thereof include: derived from acrylic acid; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and tertiary acrylate. Butyl ester, 2-ethylhexyl acrylate, dodecyl acrylate, stearyl acrylate and other unsaturated monomers with acrylate; methacrylic acid; methyl methacrylate, ethyl methacrylate, n-methacrylate Propyl ester, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, methacrylate Unsaturated monomers with methacrylate such as stearyl acrylate; acrylamide, N-methacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, diacetone Acrylamides such as acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, acrylamide propyldimethylamine; methacrylamide, N-methylmethacrylamide, N - Methacrylamides such as ethyl methacrylamide, methacrylamide propyl sulfonic acid, methacrylamide propyl dimethylamine; methyl vinyl ether, ethyl vinyl ether, n- Propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tertiary butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, 2 , Vinyl ethers such as 3-diethyloxy-1-vinyloxypropane; unsaturated nitriles such as acrylonitrile and methacrylonitrile; halogenated ethylenes such as vinyl chloride and vinyl fluoride; vinylidene chloride, Vinylidene halides such as vinylidene fluoride; allyl compounds such as allyl acetate, 2,3-diethyloxy-1-allyloxypropane, and propylene chloride; maleic acid, itaconic acid, Unsaturated dicarboxylic acids such as fumaric acid and their salts; monomethyl maleate, dimethyl maleate, methyl itaconate, dimethyl itaconate, methyl fumarate, dimethyl fumarate Methyl ester and other unsaturated dicarboxylic acid esters and their salts; vinyl trimethoxysilane and other vinyl silica compounds; isopropylene acetate; vinyl sulfonic acid; p-styrene sulfonic acid; diallyl dimethyl chloride Ammonium, vinyltrimethylammonium chloride, allyltrimethylammonium chloride, p-vinylbenzyltrimethylammonium chloride, 3-(methacrylamide)propyltrimethylammonium chloride and other ammonium salts; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl stearate, vinyl benzoate, vinyl trifluoroacetate, trimethylvinyl acetate, Vishal Structural units of vinyl esters such as vinyl dicoate, and combinations thereof.

The content of other structural units in the vinyl alcohol copolymer of the present invention is preferably 40 mol% or less, more preferably 10 mol% or less, and still more preferably 5 mol% or less. If the content rate of the hydroxyl-containing structural unit exceeds 40 mol%, the strength may decrease.

(minimum heat sealing temperature) For the vinyl alcohol copolymer of the present invention, the difference between the melting point and the minimum heat sealing temperature is 45°C or more, preferably 50°C or more, more preferably 60°C or more, or the minimum heat sealing temperature is 80°C or less, preferably 75°C. below, more preferably below 70°C. Here, the term "minimum heat sealing temperature" used in this manual refers to using a heat sealing machine in a gas environment of 23°C and 50% RH to seal the upper crimping part (10mm) and the lower crimping part ( 10mm), and a crimping force of about 0.6MPa for 1 second, heat-seal two pieces of humidity-controlled film, and use T-peel (180-degree peel test) with a width of 15mm at 300mm/min. The test speed is used to measure the breaking strength or peel strength of the heat-sealed part, and the lowest value of the temperature when the strength exceeds 5N/15mm. If the difference between the melting point and the minimum heat sealing temperature is less than 45°C, the resulting vinyl alcohol copolymer (resin) may melt, causing concerns such as insufficient heat sealing strength of the film obtained from the copolymer. In addition, there is no lower limit of the minimum heat sealing temperature. However, if it is lower than 40° C., the films obtained from the vinyl alcohol copolymer may adhere to each other during storage.

(Intensity obtained from ultraviolet absorption detector and refractive index detector in gel permeation chromatography measurement) The vinyl alcohol copolymer of the present invention is a gel permeation chromatography using a copolymer obtained by acetylation of the vinyl alcohol copolymer. During the measurement, the intensity obtained by the ultraviolet detector and the refractive index detector satisfies any of the following relational expressions. (a){U1/R1}/{U2/R2}≦0.990 or (b)1.010≦{U1/R1}/{U2/R2} (here, U1 is obtained by acetylation of the vinyl alcohol copolymer In the gel permeation chromatography measurement of the copolymer, Mn was calculated from the chromatogram obtained with the refractive index detector, and the value of the peak intensity of the chromatogram obtained from the ultraviolet absorption detector was determined using the molecular weight MU1 specified by the following formula. . Log ₁₀ MU1 = Log ₁₀ (Mn) + 0.5 R1 is Mn calculated from the chromatogram obtained by the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer. , the value of the peak intensity of the chromatogram obtained from the refractive index detector at the molecular weight MR1 specified by the following formula. Log ₁₀ MR1=Log ₁₀ (Mn)+0.5 U2 is obtained by making the vinyl alcohol copolymer B In the gel permeation chromatography measurement of the copolymer obtained by chelation, Mn was calculated from the chromatogram obtained by the refractive index detector, and the molecular weight MU2 specified by the following formula was used in the chromatogram obtained by the ultraviolet absorption detector. The value of the peak intensity in the figure. Log ₁₀ MU2=Log ₁₀ (Mn)−0.5 R2 is obtained from the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer. Calculate Mn from the chromatogram using the value of the peak intensity of the chromatogram obtained from the refractive index detector using the molecular weight MR2 specified by the following formula. Log ₁₀ MR2=Log ₁₀ (Mn)−0.5 and Mn is given by The number average molecular weight of the copolymer obtained by acetylation of the vinyl alcohol copolymer was calculated from the chromatogram obtained by the refractive index detector.)

Furthermore, the upper limit in the above formula (a) is preferably 0.985 or less, more preferably 0.980 or less, 0.975 or less, 0.970 or less, 0.950 or less, or 0.930 or less, most preferably 0.910 or less. The lower limit in the above formula (b) is preferably 1.013 or more, more preferably 1.018 or more, 1.025 or more, 1.030 or more, or 1.050 or more, or 1.070 or more, most preferably 1.100 or more.

The vinyl alcohol copolymer of the present invention can provide good heat sealability to the resulting film by satisfying the above range with formula (a) or (b).

(other features) The number average molecular weight (Mn) of the copolymer obtained by acetylating the vinyl alcohol copolymer of the present invention is preferably 400 to 200,000, more preferably 10,000 to 150,000, still more preferably 15,000 to 100,000, most preferably 20,000 to 50,000 . If the Mn of the copolymer obtained by acetylating the vinyl alcohol copolymer is less than 400, sufficient strength may not be obtained when the copolymer is formed into a film, for example. When the Mn of the vinyl alcohol copolymer is higher than 200,000, industrial production of the vinyl alcohol copolymer itself may become difficult, and the processability of the film may decrease. In addition, Mn is calculated using high performance liquid chromatography (HPLC), for example.

The degree of saponification of the vinyl alcohol copolymer of the present invention is not particularly limited, but is preferably 50 to 100 mol%. When the degree of saponification is less than 50 mol%, the resin molded article obtained by using the copolymer may not have sufficient water vapor barrier properties. The degree of saponification is more preferably 70 mol% or more, further preferably 80 mol% or more. On the other hand, the degree of saponification is preferably 99.99 mol% or less, more preferably 99.95 mol% or less, still more preferably 99.90 mol% or less. In the present invention, the degree of saponification is defined by DS represented by the following formula (S ₁ ), and is specifically calculated from the measurement results of ¹ H-NMR.

(Here, in formula (S ₁ ), D is the molar number of hydroxyl groups in the vinyl alcohol copolymer, and E is the molar number of hydroxyl groups in the vinyl alcohol copolymer and the molar number of ester groups in the vinyl alcohol copolymer. total)

(Production method of vinyl alcohol copolymer) The vinyl alcohol copolymer of the present invention is not necessarily limited, but can be produced, for example, by polymerizing a vinyl ester monomer, an olefin monomer, and/or other monomers under conditions in which the pressure of the olefin monomer fluctuates. Hereinafter, as a method for producing the vinyl alcohol copolymer of the present invention, a case in which a vinyl ester monomer, an olefin monomer, and/or other monomers are polymerized under conditions in which the pressure of the olefin monomer fluctuates is explained.

(polymerization) The polymerization of vinyl ester monomers, olefin monomers, and/or other monomers can be carried out using any polymerization method such as batch polymerization, semi-batch polymerization, continuous polymerization, or semi-continuous polymerization. However, in the case of olefin monomers, Under conditions where the pressure may fluctuate, it is preferable to perform batch polymerization, for example.

Here, the average change rate of the pressure of the olefin structural unit is 1.0×10 ^-5 Pa/min or more, preferably 10.0×10 ^-5 Pa/min or more, and more preferably 20.0×10 ^-5 Pa/min. above. If the average fluctuation rate of the pressure of the olefin structural units is less than 1.0×10 ^-5 Pa/min, the concentration of the olefin structural units in the reaction tank may decrease, making it difficult to obtain a desired vinyl alcohol copolymer. In addition, the average fluctuation speed is the absolute value of the pressure change speed (expressed as a positive value when the pressure increases and as a negative value when the pressure decreases). In addition, when multiple pressure changes such as increasing and decreasing the pressure are performed in one production, the average value of the absolute values of the respective pressure change speeds is set as the average variation speed.

In addition, as the polymerization method, well-known methods such as block polymerization method, solution polymerization method, suspension polymerization method, and emulsion polymerization method can be used.

The solvent used in the solution polymerization method is not particularly limited, but alcohol is suitably used, and lower alcohols such as methanol, ethanol, and propanol are more suitably used. The amount of solvent used in the polymerization reaction solution can be selected by considering the viscosity of the intended vinyl alcohol copolymer, the average degree of polymerization, the chain transfer of the solvent, and the mass ratio of the solvent contained in the reaction solution to all monomers (solvent/all monomers). body), it is preferably selected from the range of 0.01 to 10, and more preferably selected from the range of 0.05 to 3.

For the copolymerization of the vinyl ester monomer and the olefin monomer, for example, a known polymerization initiator can be used. The type of polymerization initiator used can be appropriately selected according to the above-mentioned polymerization method. Examples of such polymerization initiators include azo-based initiators, peroxide-based initiators, and redox-based initiators.

Examples of azo-based initiators include: 2,2-azobisisobutyronitrile, 2,2-azobis(2,4-dimethylvaleronitrile), 2,2-azobisisobutyronitrile, Azobis(4-methoxy-2,4-dimethylvaleronitrile).

Examples of peroxide-based initiators include diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diethoxyethyl peroxydicarbonate, and the like. Carbonate compounds; peroxyacid ester compounds such as tertiary butyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, and acetyl peroxide; acetylcyclohexylsulfonyl peroxide (acetyl cyclohexylsulfonyl peroxide); 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate (2,4,4-trimethylpentyl-2-peroxyphenoxyacetate), etc. When using a peroxide-based initiator, potassium persulfate, ammonium persulfate, hydrogen peroxide, etc. can be used in combination with the above-mentioned initiator.

Examples of redox-based initiators include combinations of the peroxide-based initiators described above and reducing agents such as sodium bisulfite, sodium bicarbonate, tartaric acid, L-ascorbic acid, and rongalite. By.

The usage amount of the polymerization initiator varies depending on the type of polymerization catalyst used together and is therefore not necessarily limited. However, for example, the amount can be adjusted to any amount by a person with ordinary knowledge in the technical field to which the invention pertains, depending on the polymerization speed. For example, the usage amount of the polymerization initiator is preferably 0.01 to 0.2 mol%, more preferably 0.02 to 0.15 mol% relative to the vinyl ester monomer. By using the polymerization initiator in an amount within such a range relative to the vinyl ester monomer, the copolymerization of the vinyl ester monomer and the olefin monomer can proceed more efficiently. In addition, the polymerization temperature is not particularly limited, but for example, room temperature to about 150°C is appropriate, and a temperature of 40°C or higher and below the boiling point of the solvent used is preferably selected.

In the production method of the present invention, the above-mentioned polymerization may be performed in the presence of a chain transfer agent as long as the effects of the present invention are not inhibited.

Examples of chain transfer agents include: aldehydes such as acetaldehyde and propionaldehyde; ketones such as acetone and methyl ethyl ketone; thiols such as 2-hydroxyethanethiol; sodium phosphinate monohydrate Phosphinates, etc. The amount of chain transfer agent added to the polymerization reaction solution can be determined according to the chain transfer coefficient of the chain transfer agent and the degree of polymerization of the intended vinyl alcohol copolymer, but is preferably relative to 100 parts by mass of the above-mentioned vinyl ester monomer. 0.1 to 10 parts by mass.

A crude copolymer can be produced by the above polymerization.

In the production method of the present invention, the crude copolymer obtained above can be saponified. At this time, all or part of the vinyl ester units derived from the vinyl ester monomer in the copolymer are converted into vinyl alcohol units. Different types of ester groups can be hydrolyzed simultaneously through one saponification reaction.

As for the saponification method carried out in this way, a well-known method can be used. Saponification is usually carried out in alcohol or aqueous alcoholic solutions. Alcohols suitable for use at this time include lower alcohols such as methanol and ethanol, and methanol is preferred. The alcohol or water-containing alcohol used for saponification may contain other solvents such as acetone, methyl acetate, ethyl acetate, and benzene if the mass is less than 40% by mass. Examples of catalysts used for saponification include alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, alkali catalysts such as sodium methoxide, and acid catalysts such as mineral acid. When performing saponification, the temperature is set to 20 to 120°C, for example. If a gel-like product precipitates as saponification proceeds, the product can be crushed, washed and dried.

By proceeding in this manner, the vinyl alcohol copolymer of the present invention can be produced.

(resin composition) The vinyl alcohol copolymer of the present invention can be used alone, or can be blended with other copolymers and/or additives to form a resin composition for use.

Examples of other copolymers include polyvinyl alcohol and ethylene-vinyl alcohol copolymers that do not contain hydroxyl-containing structural units other than the vinyl alcohol structural units mentioned above. More specific examples of other copolymers include: polyvinyl alcohol having a saponification degree of 40 to 100%, modified polyvinyl alcohol having a saponification degree of 40 to 100%, and polyvinyl alcohol having a saponification degree of 40 to 100%. Ethylene-vinyl alcohol copolymers with a saponification degree of 40 to 100%, polyvinyl butyral, starch, starch derivatives, cellulose and cellulose derivatives, and combinations thereof.

Examples of other additives include inorganic salts, organic salts, cross-linking agents, solvents, ultraviolet absorbers, antioxidants, antistatic agents, plasticizers, antifungal agents, and preservatives, and the like. combination. The content rates of other copolymers and other additives are not particularly limited, and appropriate amounts can be selected by those with ordinary knowledge in the technical field to which the invention belongs.

(Resin molded body) The resin molding system of the present invention is obtained from a resin composition containing the above-mentioned vinyl alcohol copolymer. The resin composition utilizes the excellent gas barrier properties (such as oxygen barrier properties and water vapor barrier properties) and maintaining processability of the above-mentioned vinyl alcohol copolymer to be molded into packaging materials that can be used for heat sealing and other purposes (such as Films including polarizing films), (binder) fibers, polarizing films, water-soluble substrates, etc.

For example, the resin molded article of the present invention may be in the form of a sealing film.

When the resin molded article of the present invention is used as a heat-sealing film, its size and thickness are not particularly limited and can be arbitrarily set according to the purpose of use by those with ordinary skill in the technical field to which the invention belongs. The heat sealing film of the present invention can be laminated with other thermoplastic resin films as a base material layer if necessary.

Examples of other thermoplastic resin films include polyolefin films (for example, polyethylene films, polypropylene films, etc.), polyester films (for example, polyethylene terephthalate films), nylon, and polypropylene. Nitrile, polyvinyl chloride and polyvinylidene chloride (PVDC), and combinations thereof. The size and thickness of other thermoplastic resin films are not particularly limited, and those with ordinary skill in the technical field to which the invention belongs can set them arbitrarily according to the purpose of use.

The vinyl alcohol copolymer and/or resin composition of the present invention can be used, for example, as a surfactant; a dispersion stabilizer for organic and inorganic pigments such as coatings and adhesives; vinyl chloride, vinylidene chloride, styrene, (methane dispersion stabilizers and dispersion aids for suspension polymerization of various vinyl compounds such as acrylic esters and vinyl acetate; adhesives; various binders; additives for cement and stucco; paper coating agents, internal additives for paper and Pigment binder and other paper modifiers; sizing agent; fiber processing agent; leather processing agent; coating; anti-fog agent; metal corrosion inhibitor; gloss agent for galvanizing; antistatic agent; medicinal coating agent; emulsion polymerization Emulsifiers; post-emulsifiers for asphalt, etc.; coagulants for suspended and dissolved substances in water; metal coagulants; fibers, sheets, pipes, tubes, leak-proof films, chemical laces, water-soluble fibers; sponges ; Water-soluble film; polarizing film; barrier film; post-reaction with low-molecular organic compounds, high-molecular organic compounds or inorganic compounds; adhesive for wood, paper, aluminum foil and inorganic substances; non-woven fabric adhesive; warp sizing agent; Fiber processing agent; sizing agent for hydrophobic fibers such as polyester; materials in the oil and fat industry; materials in the electrical and electronic fields; films; sheets; bottles; tubes; packaging containers for food, beverages, pet food, medicines, health care products, clothing, etc. ; Fuel tanks; air-conditioning pipes; vacuum insulation panels; building materials; films for soil fumigation; linings for filling; tackifiers; coagulants; soil modifiers; hydrogels; interlayer films for laminated glass Sealants for solar cells; slurry compositions for ceramics; ink compositions and coating compositions; adhesive compositions; thermally developable photosensitive material compositions, etc. [Example]

Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples. In addition, "%" and "part" in the following examples and comparative examples mean "mass %" and "mass part" respectively unless otherwise stated.

(Calculation of the content rate of each monomer unit) Examples 1 to 11 and Comparative Examples 1 to 1 were measured in deuterated dimethyl sulfoxide at 27° C. using a nuclear magnetic resonance apparatus "LAMBDA 500" manufactured by JEOL Ltd. 4. ¹ H-NMR of the obtained vinyl alcohol copolymer was used to quantify the content of each monomer unit in the polymer (olefin structural units, vinyl alcohol structural units, and hydroxyl-containing structural units other than vinyl alcohol structural units).

(Number average molecular weight (Mn), Log ₁₀ (Mn), U1/R1, U2/R2) 0.25 g of the obtained vinyl alcohol copolymer was dissolved in 2.25 g of dimethylsulfoxide at 80°C. 0.0135 g of 4-dimethylaminopyridine and 0.65 g of pyridine were mixed, and the entire amount was added dropwise to the dimethylsulfoxide solution cooled to 25°C. To this solution, 1.15 g of acetic anhydride was added and dissolved in small amounts, and the mixture was reacted at 25° C. for 1 hour to perform acetylation. The reacted solution was added to a beaker containing 100 g of water, and the precipitated solid was recovered. Acetone was added to the recovered solid so that the total weight became 5 g, and it was heated to 50° C. to dissolve it. The solution was added again to a beaker containing 100 g of water to precipitate the copolymer and collect the solid, which was dried under reduced pressure to obtain an acetylated copolymer. Using a gel permeation chromatography apparatus, the number average molecular weight (Mn), Log ₁₀ (Mn), U1/R1, and U2/R2 of the copolymer obtained by acetylating the obtained vinyl alcohol copolymer were measured.

Here, U1 is Mn calculated from the chromatogram obtained with a refractive index detector in gel permeation chromatography measurement of a copolymer obtained by acetylation of this vinyl alcohol copolymer, and the molecular weight MU1 is defined by the following formula The value of the peak intensity of the chromatogram obtained from the ultraviolet absorption detector. Log ₁₀ MU1 = Log ₁₀ (Mn) + 0.5 R1 is Mn calculated from the chromatogram obtained by the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer, The value of the peak intensity of the chromatogram obtained from the refractive index detector at the molecular weight MR1 specified by the following formula. Log ₁₀ MR1 = Log ₁₀ (Mn) + 0.5 U2 is Mn calculated from the chromatogram obtained by the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer. The value of the peak intensity of the chromatogram obtained from the ultraviolet absorption detector at the molecular weight MU2 specified by the following formula. Log ₁₀ MU2=Log ₁₀ (Mn)−0.5 R2 is Mn calculated from the chromatogram obtained by the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer, The value of the peak intensity of the chromatogram obtained from the refractive index detector at the molecular weight MR2 specified by the following formula. Log ₁₀ MR2=Log ₁₀ (Mn)−0.5 and Mn is the number average molecular weight of the copolymer obtained by acetylation of the vinyl alcohol copolymer calculated from the chromatogram obtained by the refractive index detector.

The measurement conditions are as follows. Column: Series connection of one Shodex "KF-G (4.6mm×10mm)" and two "KF-806M (4.6mm×300mm)" Standard sample: Polymethyl methacrylate (Agilent EasiVial GPC/SEC Calibration Standards Part Number PL2020-0203), MP 2,210,000, 1,020,000, 538,500, 265,000, 146,500, 72,000, 26,500, 13,900, 7,290, 1,8 40, 885, 550 Solvent and mobile phase: tetrahydrofuran (without stabilizer), purity 99.8% (manufactured by FUJIFILM Wako Pure Chemical Co., Ltd. 201-20073) Flow: 1.0mL/min Temperature: 40℃ Measurement time: 40 minutes Sample solution concentration: 0.17 mass/volume % (tetrahydrofuran (without stabilizer) solution) (filtered with a filter with a pore size of 0.45 μm) Injection volume: 100μL Ultraviolet absorption detector: SPD-20A manufactured by Shimadzu Corporation Refractive index detector: Shodex RI-501 Degassing device: Shodex ERC-3215α Liquid delivery pump: LC-20AD manufactured by Shimadzu Corporation Automatic sampler: LC-20A HT manufactured by Shimadzu Corporation Column oven: CTO-20 manufactured by Shimadzu Corporation

(Saponification degree) The content rate of each structural unit was calculated from the ¹ H-NMR measurement result of the copolymer, and the saponification degree (DS) of the polymer was obtained according to the following formula (S ₁ ).

(Here, in formula (S ₁ ), D is the molar number of hydroxyl groups in the vinyl alcohol copolymer, and E is the molar number of hydroxyl groups in the vinyl alcohol copolymer and the molar number of ester groups in the vinyl alcohol copolymer. total)

(heat sealability) Vinyl alcohol copolymer aqueous solutions obtained in Examples and Comparative Examples with a concentration of 10% by mass were prepared, filtered and centrifuged to remove foreign matter and bubbles. When the polymer is insoluble in water, it is dissolved in a mixed solution in which 2-propanol is added until it reaches a dissolved composition (the concentration of the polymer is 10% by mass). Pour the aqueous solution onto the PET film and dry it for 1 week in a gas environment of 23°C and 50% RH to obtain a film with a thickness of about 100 μm. The film was humidified under the conditions of 20°C and 60%RH. Next, cut the two films that have been humidified in this way into 1.5 cm × 5.0 cm, and overlap them so that the vinyl alcohol copolymer layers of the two films face each other and are in contact with each other. In a gas environment, use a heat sealing machine ("Heating temperature control electric sealing machine OPL-200-10" manufactured by Fuji Impulse Co., Ltd.) to determine the upper crimping part (10mm), lower crimping part (10mm), and crimping force. Heat-seal a portion of the overlapping films at various temperatures under conditions of approximately 0.6MPa and 1 second. Thereafter, the breaking strength or peel strength of the obtained heat-sealed portion was measured using T-peel (180-degree peel test) with a width of 15 mm at a test speed of 300 mm/minute.

(Tensile Strength) Vinyl alcohol copolymer aqueous solutions obtained in Examples and Comparative Examples with a concentration of 10% by mass were prepared, filtered and centrifuged to remove foreign matter and air bubbles. When the copolymer is insoluble in water, it is dissolved in a mixed solution in which 2-propanol is added until it reaches a dissolved composition (the concentration of the polymer at this time is 10% by mass). Pour the aqueous solution onto the PET film and dry it for 1 week in a gas environment of 23°C and 50% RH to obtain a film with a thickness of about 100 μm. This film was humidified at 20° C. and 40% RH for 1 week, and the stress at the maximum point was measured under the following conditions. Device: Autograph AG-X plus (manufactured by Shimadzu Corporation) Distance between clamps: 70mm Tensile speed: 500mm/min Sample shape: Dumbbell type (width 10mm, thickness approximately 0.1mm) Test environment: 23°C, 50%RH In addition, if the tensile strength is 5 kgf/mm ² or more, the strength required for practical use can be ensured.

(Crystallization melting enthalpy, glass transition temperature and melting point) The crystal melting enthalpy, glass transition temperature, and melting point were measured using the following conditions. Device: Differential scanning calorimeter (DSC25 manufactured by TA Instruments) Temperature profile: After heating up from room temperature to 250℃, cooling to -30℃, and then heating up to 250℃ again. The crystallization melting enthalpy, glass transition temperature, and melting point were determined from the final heating profile. Heating and cooling speed: 10℃/min Sample size: about 3mg (use aluminum pan)

(Example 1: Production of vinyl alcohol copolymer) In this example, unless otherwise specified, pressure means gauge pressure.

In a 1.4L pressurized reaction tank equipped with a stirrer, nitrogen inlet, propylene inlet, starter addition port and solution feed port, 500g of vinyl acetate and 150g of methanol were fed, and nitrogen was bubbled for 30 minutes and replace the reaction tank with nitrogen. Separately, a initiator solution was prepared by dissolving 2.0 g of 2,2-azobis(isobutyronitrile) (AIBN) as a radical polymerization initiator in 56 g of methanol, and bubbling nitrogen gas. Nitrogen substitution.

Next, propylene was introduced into the pressurized reaction tank so that the reaction tank pressure became 0.500 MPa. After the introduction, the gas was removed for 30 minutes until the reaction tank pressure reached 0.100 MPa. This operation of introducing propylene and removing the gas was performed a total of three times to replace the inside of the reaction tank with propylene. After raising the temperature from a state of 0.100 MPa until the internal temperature of the reaction tank reaches 60°C, propylene is introduced until the reaction tank pressure reaches 0.700 MPa. From the state where the reaction tank was at 60° C. and 0.700 MPa, the above-mentioned starter solution was added at a rate of 15 mL/min. Thereafter, the internal temperature of the reaction tank was maintained at 60°C, and the polymerization was advanced while gradually lowering the pressure of the reaction tank at a rate of 8.01×10 ^-5 MPa/min. After 337 minutes have passed since the addition of the initiator solution, when the reaction tank pressure reaches 0.673MPa and the vinyl acetate consumption rate reaches 26.8%, a polymerization inhibitor solution (4 g of 2,2,6,6-tetramethylpiperidine 1 -oxyl radical (a mixed solution of 2,2,6,6-tetramethylpiperidine 1-oxyl free radical) and 10 g of methanol) to terminate the polymerization.

After the pressurized reaction tank was opened and the propylene was removed, nitrogen was bubbled to completely remove the propylene. Next, unreacted vinyl acetate monomer was removed under reduced pressure to prepare a methanol solution of modified vinyl acetate copolymer (hereinafter also referred to as "modified PVAc"). Next, 86.1 parts by mass of a methanol solution of sodium hydroxide (the concentration of sodium hydroxide is 16.2 mass%) was added to 1000 parts by mass of a methanol solution of modified PVAc prepared by adding methanol (the concentration of modified PVAc is 14.4% by mass). %), saponify at 40°C for 15 minutes and 60°C for 2 hours. After neutralizing with acetic acid, the completion of neutralization was confirmed using a phenolphthalein indicator, and the resin was dried at room temperature to obtain a resin. This resin was pulverized, washed 5 times with 720 parts by mass of 2-propanol, and dried under reduced pressure at 40° C. for 3 days to obtain a copolymer. About 1 minute after adding the alkali, grind the gelled system with a pulverizer. After leaving it at 40°C for 1 hour to allow saponification to proceed, 1000g of methyl acetate is added to neutralize the remaining alkali. After confirming the completion of neutralization using a phenolphthalein indicator, a mixed solvent of 900 g of methanol and 100 g of water was added to the saponified white solid obtained by filtration, and the mixture was left at room temperature for 3 hours and washed. After repeating the above-mentioned washing operation three times, the saponified product obtained by centrifugal deliquidation was placed in a dryer at 70° C. for 2 days to obtain a dried vinyl alcohol copolymer. The materials and conditions used are described in Tables 1 and 2, and the evaluation results are shown in Tables 3 and 4.

(Examples 2 to 14, Comparative Examples 1 to 6, and Reference Examples 1 to 2: Production of Vinyl Alcohol Copolymer) A vinyl alcohol copolymer was produced in the same manner as in Example 1, except that the materials and reaction conditions used in Example 1 were changed as described in Tables 1 and 2. The evaluation results are shown in Tables 3 and 4.

Here, in Example 6, DAMP (1,3-diethyloxy-2-methylenepropane) as a comonomer and vinyl acetate were simultaneously fed in only the initial feed amounts described in Table 1 part. The additional portion is added gradually in the form of a methanol solution from just after adding the polymerization initiator to just before adding the inhibitor.

Furthermore, in Comparative Examples 3 and 4, after performing nitrogen substitution by bubbling nitrogen, olefin was not introduced (Table 1), and the initiator solution was added to start polymerization. The polymerization is carried out under atmospheric pressure.

Furthermore, in Example 7 and Comparative Example 4, the amount of the sodium hydroxide methanol solution was changed to 2.3 parts by weight.

In addition, in Examples 12 to 14 and Comparative Examples 5 and 6, as described in Table 1, the olefin system used 2-methacrylene, and in other cases, copolymers were synthesized and evaluated using the conditions described in Table 1.

(Refer to Examples 1 and 2) As shown in Table 1, ethylene was used for the olefin type, and for other copolymers, copolymers were synthesized under the conditions described in Table 1 and evaluated.

[Table 1] vinyl acetate Methanol starter solution comonomer Gas type Adding amount [g] Adding amount [g] AIBN[g] Methanol[g] Addition speed [mL/min] Type of monomer Initial addition amount [g] Additional volume [mL] Additional solution concentration [mass %] Example 1 500 150 2.0 56 15 - - - - Acrylic Example 2 500 150 2.0 56 15 - - - - Acrylic Example 3 500 150 2.0 56 15 - - - - Acrylic Example 4 400 380 2.0 50 15 - - - - Acrylic Example 5 400 380 2.0 50 15 - - - - Acrylic Example 6 400 358 2.0 50 20 DAMP 15 64 20 Acrylic Example 7 500 150 2.0 56 15 - - - - Acrylic Example 8 500 156 2.0 50 15 - - - - Acrylic Example 9 500 81 4.0 80 15 - - - - Acrylic Example 10 500 81 4.0 80 15 - - - - Acrylic Example 11 400 380 2.0 50 15 - - - - Acrylic Example 12 400 403 1.5 30 15 - - - - 2-Methylpropene Example 13 400 422 1.5 30 15 - - - - 2-Methylpropene Example 14 400 422 1.5 30 15 - - - - 2-Methylpropene Comparative example 1 500 150 2.0 56 15 - - - - Acrylic Comparative example 2 400 380 2.0 50 15 - - - - Acrylic Comparative example 3 400 767 0.8 40 15 - - - - without Comparative example 4 400 767 0.8 40 15 - - - - without Comparative example 5 400 403 1.5 30 15 - - - - 2-Methylpropene Comparative example 6 400 422 1.5 30 15 - - - - 2-Methylpropene Reference example 1 250 487 0.5 20 15 - - - - Ethylene Reference example 2 250 487 0.5 20 15 - - - - Ethylene DAMP: 1,3-diethyloxy-2-methylenepropane

[Table 2] pressure Aggregation time [minutes] Vinyl acetate consumption rate [mass %] When adding starter solution [MPa] When polymerization inhibitor solution is added [MPa] Pressure change speed [10 ^-5 MPa/min] Example 1 0.698 0.682 -4.7 337 27.2 Example 2 0.700 0.673 -8.0 337 26.8 Example 3 0.730 0.631 -29.4 337 26.7 Example 4 0.499 0.400 -29.3 338 36.0 Example 5 0.265 0.231 -15.5 220 39.2 Example 6 0.458 0.427 -8.2 377 28.4 Example 7 0.700 0.673 -8.0 337 26.8 Example 8 0.700 0.738 10.9 348 27.0 Example 9 0.724 0.824 15.5 646 59.3 Example 10 0.680 0.881 58.3 345 59.3 Example 11 0.210 0.221 5.8 191 43.6 Example 12 0.140 0.130 -5.3 188 37.0 Example 13 0.106 0.081 -7.6 328 41.3 Example 14 0.180 0.158 -8.5 260 27.1 Comparative example 1 0.680 0.680 0 337 27.2 Comparative example 2 0.250 0.250 0 220 39.2 Comparative example 3 - - - 242 41.5 Comparative example 4 - - - 242 41.5 Comparative example 5 0.135 0.135 0 186 36.9 Comparative example 6 0.170 0.170 0 266 27.3 Reference example 1 0.361 0.361 0 131 38.2 Reference example 2 0.382 0.335 -35.9 131 37.8

[table 3] Modifying group of olefin unit Content of olefin units Content of vinyl alcohol units Content of vinyl acetate units Saponification degree Comonomer content melting point Minimum heat sealing temperature Melting point − minimum heat sealing temperature distributed [mol%] [mol%] [mol%] [mol%] [mol%] [℃] [℃](strength 5[N/15mm] or more) [℃] Log ₁₀ (Mn) U1/R1 U2/R2 {U1/R1}/ {U2/R2} Example 1 Acrylic 15.7 84.3 0 100 0 156 100 56 4.638 2.327 2.285 1.018 Example 2 Acrylic 15.8 84.2 0 100 0 154 100 54 4.652 2.360 2.200 1.073 Example 3 Acrylic 16.2 83.8 0 100 0 153 80 73 4.651 2.570 1.958 1.313 Example 4 Acrylic 12.5 87.3 0.1 99.9 0 173 100 73 4.669 2.278 2.252 1.012 Example 5 Acrylic 7.4 92.5 0.1 99.9 0 197 140 57 4.727 2.750 2.520 1.091 Example 6 Acrylic 14.5 81.0 0.2 99.8 4.4 143 80 63 4.738 2.326 2.296 1.013 Example 7 Acrylic 15.8 74.6 9.6 88.6 0 143 80 63 4.662 2.340 2.220 1.054 Example 8 Acrylic 16.6 83.4 0 100 0 146 80 66 4.732 2.410 2.670 0.903 Example 9 Acrylic 15.9 84.1 0 100 0 141 80 61 4.614 2.360 2.520 0.937 Example 10 Acrylic 16.3 83.5 0.2 99.8 0 140 80 60 4.704 2.141 2.876 0.744 Example 11 Acrylic 6.2 93.8 0 100 0 188 100 88 4.728 2.500 2.590 0.965 Example 12 2-Methylpropene 4.1 95.7 0.2 99.8 0 211 140 71 4.641 2.324 2.274 1.022 Example 13 2-Methylpropene 8.0 91.3 0.6 99.3 0 191 120 71 4.653 2.347 2.201 1.066 Example 14 2-Methylpropene 12.0 87.9 0.2 99.8 0 155 100 55 4.681 2.425 2.147 1.129 Comparative example 1 Acrylic 15.9 84.1 0 100 0 160 120 40 4.620 2.380 2.400 0.992 Comparative example 2 Acrylic 6.8 93.1 0.1 99.9 0 204 160 44 4.727 2.510 2.493 1.007 Comparative example 3 - 0 98.5 1.5 98.5 0 232 190 42 - - - - Comparative example 4 - 0 88.2 11.8 88.2 0 195 170 25 - - - - Comparative example 5 2-Methylpropene 4.2 95.5 0.3 99.7 0 212 160 52 4.684 2.355 2.338 1.007 Comparative example 6 2-Methylpropene 12.3 87.5 0.2 99.8 0 158 120 38 4.689 2.419 2.407 1.005 Reference example 1 Ethylene 8.0 92.0 0 100 0 215 190 25 4.492 2.620 2.400 1.092 Reference example 2 Ethylene 8.1 91.9 0 100 0 219 190 29 4.495 2.790 2.540 1.098

[Table 4] Modifying group of olefin unit Ethylene unit content Content of vinyl alcohol units Heat sealing strength [N/15mm] tensile strength crystallization melting enthalpy glass transition temperature [mol%] [mol%] 80℃ 90℃ 100℃ 120℃ 140℃ 160℃ 170℃ 190℃ [kgf/mm ² ](40%RH) [J/g] [℃] Example 1 Acrylic 15.7 84.3 - 0.2 6.8 26.4 30.2 29.8 - - 12.50 18.5 76.5 Example 2 Acrylic 15.8 84.2 - 0.6 27.5 28.0 33.9 30.2 - - 12.77 17.9 75.3 Example 3 Acrylic 16.2 83.8 15.4 24.8 26.1 26.2 26.0 25.4 - - 12.10 16.8 74.4 Example 4 Acrylic 12.5 87.3 - - 5.1 31.7 31.4 39.5 - - 12.29 24.1 78.3 Example 5 Acrylic 7.4 92.5 - - Not followed 3.0 33.9 35.0 - - 13.37 28.5 81.0 Example 6 Acrylic 14.5 81.0 20.8 24.8 29.6 25.6 25.8 25.8 - - 12.53 15.5 71.9 Example 7 Acrylic 15.8 74.6 22.5 25.7 26.3 - - - - - 9.83 12.8 68.3 Example 8 Acrylic 16.6 83.4 20.0 25.4 26.6 - - - - - 10.51 21.4 74.1 Example 9 Acrylic 15.9 84.1 23.2 18.3 23.7 - - - - - 11.63 9.0 69.9 Example 10 Acrylic 16.3 83.5 25.8 23.6 24.8 - - - - - 10.10 8.3 65.8 Example 11 Acrylic 6.2 93.8 - - 13.8 21.4 27.5 - - - 5.82 26.9 68.4 Example 12 2-Methylpropene 4.1 95.7 - - - 2.1 33.5 35.7 - - 12.10 55.2 80.9 Example 13 2-Methylpropene 8.0 91.3 - - 4.8 31.8 31.6 32.8 - - 12.50 25.5 76.9 Example 14 2-Methylpropene 12.0 87.9 - 0.5 25.8 27.8 28.6 28.7 - - 10.80 19.2 77.1 Comparative example 1 Acrylic 15.9 84.1 - 0.4 3.3 26.2 33.1 29.1 - - 11.85 19.3 77.2 Comparative example 2 Acrylic 6.8 93.1 - - Not followed 2.1 3.5 33.0 - - 10.21 29.8 81.7 Comparative example 3 - 0 98.5 - - - - 0.2 0.4 1.2 6.8 13.15 95.7 81.0 Comparative example 4 - 0 88.2 - - - - 0.7 3.2 29.0 28.4 11.60 28.9 70.4 Comparative example 5 2-Methylpropene 4.2 95.5 - - - 0.5 2.8 29.7 - - 9.22 57.6 81.0 Comparative example 6 2-Methylpropene 12.3 87.5 - Not followed 4.2 23.4 27.1 27.9 - - 8.97 20.1 77.5 Reference example 1 Ethylene 8.0 92.0 - - - - 0.4 4.0 4.3 19.0 10.94 70.0 73.9 Reference example 2 Ethylene 8.1 91.9 - - - - 0.6 3.9 4.1 18.9 9.90 67.6 74.9

As shown in Tables 3 and 4, a copolymer obtained by polymerizing an olefin while reducing the pressure of an olefin has a lower minimum heat-sealable temperature than a copolymer obtained by polymerizing an olefin under a constant pressure. (For example, compare and refer to Examples 1 to 3 and Comparative Example 1. Compare and refer to Example 5 and Comparative Example 2). In addition, the heat-sealable temperature of a copolymer obtained by polymerizing an olefin while increasing the pressure of an olefin is further lower than that of a copolymer obtained by polymerizing an olefin with a constant pressure (for example, compare and refer to Examples 8 to 10 and Comparative Example 1. Compare and refer to Example 11 and Comparative Example 2). In addition, a copolymer obtained by polymerizing an olefin while reducing the pressure of an olefin tends to have better tensile strength than a copolymer obtained by polymerizing an olefin under a constant pressure (for example, compare and refer to Example Examples 1 to 3 and Comparative Example 1. Compare and refer to Example 5 and Comparative Example 2). Furthermore, when ethylene is used as the olefin, there is no difference in the minimum heat-sealable temperature between a copolymer obtained by polymerizing the olefin while reducing the pressure of the olefin and a copolymer obtained by polymerizing the olefin at a constant pressure ( Compare and refer to Reference Examples 1 and 2).

In addition, as shown in Tables 3 and 4, when 2-methylpropylene is used as the olefin, the heat-sealable temperature will be lower than when propylene is used (for example, compare and refer to Example 5 where the content of the olefin unit is the same) and Example 13. Compare and refer to Example 4 and Example 14). [Possibility of industrial application]

The resin composition of the present invention is useful in technical fields such as food and beverage fields, pet food fields, oil and fat industry fields, pharmaceutical fields, and electrical and electronic fields.

without

without

without.

Claims (22)

A vinyl alcohol copolymer containing vinyl alcohol structural units and olefin structural units with a carbon number of 3 to 30. The copolymer satisfies the requirement that the difference between the melting point and the minimum heat sealing temperature is 45°C or more, and the minimum heat sealing temperature is 80°C or less. At least one, and satisfy the following formula, {U1/R1}/{U2/R2}≦0.990 or 1.010≦{U1/R1}/{U2/R2} Here, U1 is made of the vinyl alcohol copolymer B In the gel permeation chromatography measurement of the copolymer obtained by chelation, Mn was calculated from the chromatogram obtained by the refractive index detector, and the peak of the chromatogram obtained by the ultraviolet absorption detector was determined using the molecular weight MU1 specified by the following formula. The intensity value, Log ₁₀ MU1 = Log ₁₀ (Mn) + 0.5 R1 is the chromatogram obtained from the refractive index detector in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer. Mn is calculated from the figure, and the value of the peak intensity of the chromatogram obtained from the refractive index detector using the molecular weight MR1 specified by the following formula, Log ₁₀ MR1 = Log ₁₀ (Mn) + 0.5 U2 is obtained by making the vinyl alcohol In the gel permeation chromatography measurement of the copolymer obtained by acetylation of the copolymer, Mn was calculated from the chromatogram obtained by the refractive index detector, and the molecular weight MU2 specified by the following formula was obtained from the ultraviolet absorption detector. The value of the peak intensity of the chromatogram, Log ₁₀ MU2=Log ₁₀ (Mn)-0.5 R2 is obtained from the refractive index in the gel permeation chromatography measurement of the copolymer obtained by acetylation of the vinyl alcohol copolymer. Mn is calculated from the chromatogram obtained by the detector, using the value of the peak intensity of the chromatogram obtained by the refractive index detector using the molecular weight MR2 specified by the following formula, Log ₁₀ MR2=Log ₁₀ (Mn)-0.5 and Mn is the number average molecular weight of the copolymer obtained by acetylating the vinyl alcohol copolymer, calculated from the chromatogram obtained by the refractive index detector. The vinyl alcohol copolymer of claim 1, wherein the number of carbon atoms contained in the aforementioned olefin structural unit is 3 to 9. The vinyl alcohol copolymer of claim 2, wherein the aforementioned olefin structural unit is selected from the group consisting of propylene unit, 1-butene unit, cis-2-butene unit, trans-2-butene unit, and 2-methacrylene unit. , 1-pentene unit, cis-2-pentene unit, trans-2-pentene unit, 2-methyl-1-butene unit, 2-methyl-2-butene unit, 3-methyl- 1-butene unit, 1-hexene unit, 1-heptene unit, 1-octene unit, 1-nonene unit, 2-methyl-1-octene unit, and 7-methyl-1-octene unit At least one structural unit in the group of olefin units. The vinyl alcohol copolymer of claim 3, wherein the aforementioned olefin structural unit is selected from the group consisting of propylene unit, 1-butene unit, cis-2-butene unit, trans-2-butene unit, and 2-methylpropylene. At least one structural unit in the group of units. The vinyl alcohol copolymer of claim 4, wherein the aforementioned olefin structural unit is a propylene unit. The vinyl alcohol copolymer of claim 4, wherein the aforementioned olefin structural unit is a 2-methylpropylene unit. The vinyl alcohol copolymer according to any one of claims 1 to 6, wherein the content of the olefin structural unit is 0.1 to 60 mol%. The vinyl alcohol copolymer according to any one of claims 1 to 7, wherein the number average molecular weight (Mn) of the copolymer obtained by acetylating the aforementioned vinyl alcohol copolymer is 400 to 200,000. For example, the vinyl alcohol copolymer of any one of claims 1 to 8 has a saponification degree of 50 to 100 mol%. The vinyl alcohol copolymer of any one of claims 1 to 9, wherein the content of the vinyl alcohol structural units is 75 to 99 mol%. The vinyl alcohol copolymer of any one of claims 1 to 10, which further contains hydroxyl-containing structural units other than the aforementioned vinyl alcohol structural units. The vinyl alcohol copolymer of any one of claims 1 to 11, which further contains ethylene structural units. A resin composition containing the vinyl alcohol copolymer according to any one of claims 1 to 12. The resin composition of claim 13, which further contains polyvinyl alcohol with a saponification degree of 40 to 100%, modified polyvinyl alcohol with a saponification degree of 40 to 100%, and polyvinyl alcohol with a saponification degree of 40 to 100%. At least one polymer from the group consisting of ethylene-vinyl alcohol copolymer with a saponification degree of 40 to 100%, polyvinyl butyral, starch, starch derivatives, cellulose and cellulose derivatives. A resin molded article containing the resin composition according to claim 13 or 14. The resin molded article of claim 15 is a film. The resin molded article of Claim 15 is a fiber. The resin molded article of claim 15 is a gas barrier material. The resin molded article of claim 15 is a polarizing film. The resin molded article of claim 15 is a water-soluble base material. A method for manufacturing a vinyl alcohol copolymer. The vinyl alcohol copolymer contains vinyl alcohol structural units and olefin structural units with a carbon number of 3 to 30, and satisfies the difference between the melting point and the minimum heat sealing temperature of 45°C or more, and the minimum heat sealing temperature. At least one temperature is below 80°C, The production method includes the steps of polymerizing an olefin and vinyl acetate under conditions in which the pressure of the olefin fluctuates to obtain a crude copolymer; The step of saponifying the crude copolymer. The method for producing a vinyl alcohol copolymer according to claim 21, wherein the average change speed of the pressure of the olefin is 1.0×10 ^-5 Pa/min or more.